The combined approach of repeated neuropsychological testing and magnetic resonance imaging (MRI) shows great promise as means to monitor the progression of AD. At present it is difficult to identify the specific relationship between the neurodegenerative and behavioral deficits. With the high resolution of the current MRI technology it is possible to image small discrete areas of the brain. This provides an opportunity to quantify anatomical changes in the brain prior to autopsy. Accordingly these experiments will involve volumetric changes in select brain regions of patients with AD using MRI. This will involve volumetric measures of brain structures involved in Alzheimer's neuropathology, focusing on the entorhinal/hippocampal complex. We will develop the accuracy of the present MRI by determining the variation of images and actual histological brain measurements. The long-term goal will be to correlate the volumetric changes in the MRI brain images with progressive neural degeneration and hippocampal plasticity. Behavioral measures will be used to correlate the impact of neural degenerating on cognitive function. Olfactory function is of particular interest since the degenerating structures are intimately involved in the sense of smell as well as memory. The cognitive measures will include assessment of ability to identify and recall olfactory, visual- spatial and verbal information. Behavioral and anatomical data will be further analyzed to determine the relationship between test performance and neural degeneration. We will follow the progression of the behavioral and structural degeneration during the process of AD by repeated testing and MRI scanning.